Priority is claimed herein with respect to European Patent Application No. 01810132.9, filed in the European Patent Office on Feb. 8, 2001, the subject matter of which is incorporated herein by reference.
The invention relates to a device for feeding printed products to a conveying channel, in which the printed products are conveyed with the aid of carriers installed at a distance to each other on a conveying element. The device includes an apparatus for pre-accelerating the supplied printed products in a conveying direction of the conveying channel.
European Patent Application No. 0 738 682 A, incorporated herein by reference, describes a device used to insert supplements into an insertion channel having a conveying chain. The chain is provided with regularly spaced, finger-type drivers that project into the insertion channel. The supplements are pulled with a withdrawal or pull-off roller from a stack and fed to two rotating vacuum platforms or discs via belts moving perpendicular to the conveying direction of the insertion channel. The essentially horizontally positioned vacuum discs rotate in the same direction and are respectively provided with an intake opening connected within a range of approximately 90xc2x0 to a suction channel. Approximately half of each vacuum disc is positioned inside the insertion channel. The supplements to be supplied are transferred with the belts to the two vacuum discs and are seized by the vacuum force at the intake openings. The rotation of the two vacuum discs respectively imposes a translatory movement onto the seized supplement to accelerate the supplement in the conveying direction of the insertion channel. This acceleration of the supplement serves to pre-accelerate the supplement relative to the insertion channel. The pre-acceleration reduces the force exerted by the drivers onto the edge of the printed product.
Since only one surface of the product can be seized by the rotating vacuum platforms, this known device only permits the processing of lightweight and stable individual sheets within a limited format range.
It is an object of the invention to provide a device of the aforementioned type, which permits the processing of unstable printed products and products with differing formats.
The above and other objects are solved by the present invention wherein, in the context of the device first mentioned above, a conveying means conveys the printed products in a straight line and supplies the products at an angle to the conveying direction of the conveying channel. The slanted conveying direction of printed products makes it possible to realize a shorter spacing between carriers of the conveying channel than would be otherwise possible with an apparatus that conveys the products in a direction perpendicular to the conveying channel. The present invention also enables a lower transporting speed of the products withdrawn from the stack. Besides the pre-acceleration in the conveying direction of the conveying channel, the slanted feeding also reduces the speed component extending at a right angle to the channel and leads to a reduction of the force of the carriers onto the edge of each printed product. The reduction of the speed component, extending at a right angle to the conveying channel, also reduces the speed with which the printed products impact an opposite arranged guide wall of the conveying channel. Another advantage of the device according to the present invention is that it can be used with supplements as well as main products.
According to one modification of the invention, comparably thin individual sheets as well as thick main products can be fed into the conveying channel or inserted into other passing printed products passing.
According to another modification, the conveyor belt drive is integrated directly into a drum feeder, which results in particularly good ergonomic conditions for manually supplying the feeder. A short distance between the feeder shaft and the conveying channel permits manual feeding and operation from the channel side. This integration is particularly advantageous structurally and is reliable, according to another modification of the invention, if the rollers on a withdrawing drum are positioned at an angle and the printed products are conveyed by these rollers at an angle to the conveying direction of the conveying channel. Identically aligned inner and outer belts are preferably arranged around these slanted rollers to convey the printed products into the conveying channel. Guide rods extending parallel to the rotational axis of the withdrawing drum preferably carry the slanted rollers. A drum feeder of this type is disclosed, for example, in European Patent Application 1024099, incorporated herein by reference.
Further advantageous features follow from the description below and the drawings.